A4221 HCPCS code: Supplies for maintenance of non-insulin drug infusion catheter, per week (list drugs separately)

A4221 is the HCPCS Level II code for supplies for maintenance of non-insulin drug infusion catheter, per week (list drugs separately). The 2026 Medicare DMEPOS fee schedule pays $25.87 to $32.30 depending on the state. Its Medicare coverage code is C (Carrier judgment): Coverage is decided by the Medicare contractor (MAC) case by case. The NCCI unit limit is 4 per day on DME suppliers. In 2024, 532 suppliers billed Medicare for A4221 (purchases), serving 12,861 beneficiaries; Florida, California, Texas accounted for 26% of services. Its average fee ranks 14 of 18 A42 codes (family range $0.61–$273.28); rural fees run 11% higher.

Code details

2026 Medicare DMEPOS fee schedule for A4221

How the A4221 fee compares

Who bills A4221 (2024)

Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.

Medicare utilization for A4221, 2022–2024

States with the most A4221 services (2024)

NCCI unit limits (MUE)

Medicare policy articles for this code

• A52507: External Infusion Pumps - Policy Article (CGS Administrators, LLC (DME MAC) Noridian Healthcare Solutions, LLC (DME MAC)) — mentions this code in its coding guidance
• A54563: Surgical Dressings - Policy Article (CGS Administrators, LLC (DME MAC) Noridian Healthcare Solutions, LLC (DME MAC)) — mentions this code in its coding guidance

Covered diagnoses (460 ICD-10-CM codes)

The diagnoses most often listed as covered in the policy articles above:

Showing 10 of 460. The full list, non-covered diagnoses and CSV export are in Caduvo.

What changed for A4221

• 2026-01-01: Average state fee rose 2.6%: $25.52 to $26.19
• 1997-01-01: A4221 added to HCPCS Level II
• Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01

Frequently asked questions

What is HCPCS code A4221?

A4221 is the HCPCS Level II code for supplies for maintenance of non-insulin drug infusion catheter, per week (list drugs separately). Short descriptor: "Supp non-insulin inf cath/wk".

How much does Medicare pay for A4221?

Under the 2026 DMEPOS fee schedule, non-rural state fees are base (base fee): $25.87–$32.30. Rural fees can be higher.

Does Medicare cover A4221?

Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.

Which diagnoses support coverage for A4221?

Medicare policy articles that cite A4221 list 460 covered ICD-10-CM diagnosis codes across 2 articles. The most cited include C91.00 (Acute lymphoblastic leukemia not having achieved remission), C91.01 (Acute lymphoblastic leukemia, in remission), C91.02 (Acute lymphoblastic leukemia, in relapse). A listed diagnosis is necessary but not sufficient; the policy's other criteria still apply.

Did the Medicare fee for A4221 change in 2026?

The average non-rural state fee moved from $25.52 in 2025 to $26.19 in 2026 (+2.6%). CMS's next quarterly HCPCS and DMEPOS update takes effect January 1, 2027.

How many units of A4221 can be billed per day?

4 on DME suppliers; 1 on outpatient hospital claims (NCCI medically unlikely edits).

Related A42 codes

• A4206 — Syringe with needle, sterile, 1 cc or less, each
• A4207 — Syringe with needle, sterile 2 cc, each
• A4208 — Syringe with needle, sterile 3 cc, each
• A4209 — Syringe with needle, sterile 5 cc or greater, each
• A4210 — Needle-free injection device, each
• A4211 — Supplies for self-administered injections
• A4212 — Non-coring needle or stylet with or without catheter
• A4213 — Syringe, sterile, 20 cc or greater, each
• A4215 — Needle, sterile, any size, each
• A4216 — Sterile water, saline and/or dextrose, diluent/flush, 10 ml ($0.53–$0.99)
• A4217 — Sterile water/saline, 500 ml ($2.18–$4.93)
• A4218 — Sterile saline or water, metered dose dispenser, 10 ml

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Next steps

• Run a reimbursement report for a device billed under A4221
• Watch A4221 for fee, coverage and descriptor changes
• Build a full Medicare revenue model for A4221

Sources: CMS HCPCS Level II release October 2025; CMS DMEPOS fee schedule 2026; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.

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